After a 15 year hiatus, I'm going to resume reloading. My propellant powders are 15 -30 years old. Several cans are factory sealed. The opened cans smell like solvent and are not discolored. All have been kept in n sealed magazines in cool and dehumidified basement. A representative of a US seller of "three brands" told me they should be good to use.
Does anyone disagree?